from urllib.parse import urlencode

import requests

url="http://login.aspx?"
ID='simon'
PWD='123'
VC='验证码内容'
params={
    'id':ID,
    'password':PWD,
    'validationcode':VC,
}
complete_url = url + urlencode(params)
f = requests.get(url=complete_url)
